com.khubla.jvmbasic.jvmbasicc.function.impl.rule.gotostmtRule.java Source code

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Here is the source code for com.khubla.jvmbasic.jvmbasicc.function.impl.rule.gotostmtRule.java

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package com.khubla.jvmbasic.jvmbasicc.function.impl.rule;

/*
 * jvmBasic Copyright 2012, khubla.com
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
import org.objectweb.asm.Label;
import org.objectweb.asm.Opcodes;

import com.khubla.jvmbasic.jvmbasicc.compiler.GenerationContext;
import com.khubla.jvmbasic.jvmbasicc.function.BaseFunction;

/**
 * @author tome
 */
public class gotostmtRule extends BaseFunction {
    @Override
    public boolean execute(GenerationContext generationContext) throws Exception {
        try {
            /*
             * we expect 2 arguments
             */
            if (generationContext.getParseTree().getChildCount() == 2) {
                /*
                 * get the line number
                 */
                final int lineNumber = Integer.parseInt(generationContext.getChildValue(1));
                /*
                 * find the label for the line number
                 */
                final Label label = GenerationContext.getProgramStaticAnalysis().getLinesDatabase()
                        .getLine(lineNumber).getLabel();
                /*
                 * check
                 */
                if (null != label) {
                    /*
                     * generate the goto jmp to the label
                     */
                    generationContext.getMethodVisitor().visitJumpInsn(Opcodes.GOTO, label);
                } else {
                    throw new Exception("Could not find label for BASIC line number '" + lineNumber + "'");
                }
            }
            return true;
        } catch (final Exception e) {
            throw new Exception("Exception in execute", e);
        }
    }
}